diff -r 000000000000 -r 6474c204b198 toolkit/components/url-classifier/ChunkSet.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/url-classifier/ChunkSet.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,57 @@
+//* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ChunkSet_h__
+#define ChunkSet_h__
+
+
+#include "Entries.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+namespace safebrowsing {
+
+/**
+ * Store the chunk numbers as an array of uint32_t. We need chunk numbers in
+ * order to ask for incremental updates from the server.
+ * XXX: We should optimize this further to compress the many consecutive
+ * numbers.
+ */
+class ChunkSet {
+public:
+  ChunkSet() {}
+  ~ChunkSet() {}
+
+  nsresult Serialize(nsACString& aStr);
+  nsresult Set(uint32_t aChunk);
+  nsresult Unset(uint32_t aChunk);
+  void Clear();
+  nsresult Merge(const ChunkSet& aOther);
+  nsresult Remove(const ChunkSet& aOther);
+
+  bool Has(uint32_t chunk) const;
+
+  uint32_t Length() const { return mChunks.Length(); }
+
+  nsresult Write(nsIOutputStream* aOut) {
+    return WriteTArray(aOut, mChunks);
+  }
+
+  nsresult Read(nsIInputStream* aIn, uint32_t aNumElements) {
+    return ReadTArray(aIn, &mChunks, aNumElements);
+  }
+
+  uint32_t *Begin() { return mChunks.Elements(); }
+  uint32_t *End() { return mChunks.Elements() + mChunks.Length(); }
+
+private:
+  nsTArray<uint32_t> mChunks;
+};
+
+}
+}
+
+#endif